GSM is a technology which is the leading cell phone standard all over the world. In 1982 it was recognized as a standard for digital wireless communications and was first adop…ted in Europe and then by Asia, Africa etc. The first system was online in 1991 and GSM was formerly known as Group Special Mobile but now stands for Global System for Mobile communications. USA, however has not adopted GSM as a standard and so different carriers now use different technologies as opposed to only GSM. GSM uses digital technology and the methods of time division multiple access transmission. In GSM, sound is digitally prearranged through a special encoder, which imitates the distinctiveness of human speech. This method of transmission allows a very competent statistics speed/information content ratio. GSM is an open system and is a non propriety technology. One of the great benefits of GSM is that it facilitates international roaming. As it is adopted by more than 170 countries, you have the facility of using your GSM cell phone in all these places without having to change your number. GSM satellite roaming has broadened the scope of cellular services even to areas where standard terrestrial services are not possible. GSM is a technology that is rapidly growing and constantly evolving with wireless, satellite and cordless systems offering greatly expanded services. These services include multimedia data services, high speed, inbuilt support for side by side use of these services and faultless incorporation with the Internet and wireline networks. 3GSM (next generation of mobile communications services) is already charted out and will make available services enhancing the already existing voice, data, and text services. GSM will provide video on demand and will help to lessen the gap between wireless and internet/computers. GSM works on different frequency bands across the world. In North America it uses a 1900 MHz frequency whereas in other parts of the world it uses either 900MHz or 1800 MHz. As different frequencies are used in different places, your GSM handset should support various bands so that it can be used globally. From the beginning, GSM has been developed with the need to give its customers utmost security in terms of secure communications, fraud prevention, and call privacy. Today it is the worlds most secure public wireless standard for cellular phones. In an entirely different context, GSM could also stand for grams per square metre. This is the standard measure used for paper, and fabrics.

Majority of the carriers worldwide use GSM technology, wherein SIM cards are utilized to store information, like contacts, and data. With this technology, it's just easy to us…e different phones without losing data or contacts.

The Limitations of GSM However, GSM is a technology of the mid 1980s where the only usage envisaged for a mobile phone is that of transmitting and receiving voice data. In fac…t, basic GSM phones only send and receive data at an apalling transmission rate of 9.6 kbps (kilobits per second). However, as mobile phones have grown into multimedia devices and text messaging has proved to be the 'killer app' - the one usage that brought mass appeal to mobile phones - then the data throughput limit has proved to be a real bottleneck. It's even possible to access the text content of web pages that have been converted to WAP (Wireless Access Point) format with a GSM phone. Unfortunately, due to the slow data transfer of GSM phones it can actually take several minutes to download even a WAP-converted page to your phone. In Japan this limitation was overcome by the DoCoMo company with their extremely successful I-mode range of mobile phones which can transfer data at ten times the speed of standard GSM. Standard GSM uses circuit switching as a means of data transfer. This means that the phone must make a dedicated connection with the base station thus tying-up the channel completely for that phone. In contrast, I-mode uses technology borrowed from the Internet, called packet switching where the transferred data is broken up into blocks called 'packets'. Each packet is labelled with the address of the final destination and any packet can be transferred on any available channel and no channel is dedicated to any telephone. Because of this data transfer proceeds at a much, much, higher rate. Not only are downloads quicker, but as the phone is only connected to the network when a package of information is being sent users pay for the amount of data they have sent rather than for the total time they remain connected. It is planned that all GSM networks will move to packet switching technology, which can only be of benefit to customers and it envisaged that data transfer rates will reach up to 171 kbps with the introduction of a system called GPRS (General Packet Radio Service) which not only splits the mobile phone call into packets but also allows each phone to use several channels which are shared amongst many users. Thus not only is data transfer speed increased but overall throughput is also increased. Beyond GSM - 3G 3G, which stands for 'Third Generation' is the great white hope of many mobile operators. The International Telecommunication Union (ITU) has defined the demands for third generation mobile networks with the IMT-2000 standard. An organisation called 3GPP has continued that work by defining a mobile system that fulfils the IMT-2000 standard. This system is called Universal Mobile Telecommunications System (UMTS). The first stage in the evolution of GSM to UTMS is the introduction of GPRS to all GSM services. Another advance in 3G systems is CDMA (Code Division Multiple Access) which allows a single 'burst' of data to carry several signals simultaneously. This further compresses the amount of data that can be sent in a single data burst and, theoretically at least, allows for a maximum data transfer rate of up to 2 Mbps (megabits per second). It is this increased data transfer rates that allows 3G services to deliver video to its subscribers and which should also allow video messaging between 3G mobile phones. It is the hope of the nascent 3G providers that this video communication will be 'killer application' that drive through the sales of 3G phones and systems (just as texting did for GSM).